There are a lot of variables that constitute the sound I think. Mostly the exotic speaker enclosures, not to mention being a tube based voice if I am not mistaken.

The ring on a string is the big attention grabber, I have been toying with the mechanics of it here and there for a while. I may be able to fashion a crude one when I buckle down and get on with it.

I think a reasonable copy would be worth a hell of a lot of effort, I know I would certaibnly put it in. Can anybody slip Johny Greenwood some sleeping pills, gingerly dismantle his, and take tons of high res photos please??

haha, wish I could do that, although I have heard the one that he really likes (not the french connection one) is one of only like fifty and extremely hard to reproduce. Anyway, I wish I had the skills to even come up with a design, if anyone tries to make one, even a crude one, im sure alot of people would like to know how to build it.

I did a bit of repair work on one, used in, (I think), a Messian concert at Liverpool. I was repairing one of the amplifiers, so never saw the main sound generating section.

I did form a few impressions, however. I think that it might have been a Beat Frequency Oscillator type device, and that the cord was operating a variable capacitor, altering the tuning of one of the oscillators. I think the same effect was had with a smaller unit attached to the keyboard, to allow the famous 'moving key vibrato' effect.

Ther is a good description on Wikipedia. Oher sites can be googled up quite easily.

Here is a link to a modern day reproduction data sheet: it's in French, but a lot can be read from it. From the design, I expect the repro to cost about the same as a Buchla, and I know which one I'd buy if I had the money. http://www.cslevine.com/ondea/ondeanotice1.pdf

THe sliding ring/ribbon device is only part of the design: the expression 'block' is equally important.

The sound you hear in concert is part due to the 'Duffuseurs' - the modified loudspeakers. They would be a real challenge to model electronically._________________Mike

Well, it's different. Your Appendage can do many thing the OM cannot. I've been trying to think of how to add touch control to a ribbon controller, without much luck. Maybe control with the other hand really is the way to go.

I wonder how he keeps the string from slipping over the pulley with the pot. Anybody know any more details?

I feel kinda dumb for never having considered using a wire loop with pulleys. I did not think that the wire would provide enough traction to turn the pulley consistently...but Dana's video makes it look like it will.

Does anyone know if the Ondes wire is a loop? I seem to remember seeing a video where the player not only moved it side to side but pulled the ring in towards himself a bit.

The idea I was messing about with included a pair of the tensioners from matched tape measures, and a 10 turn pot. I think i will try the pulley idea first as it appears to be more simple.

I feel kinda dumb for never having considered using a wire loop with pulleys. I did not think that the wire would provide enough traction to turn the pulley consistently...but Dana's video makes it look like it will.

Does anyone know if the Ondes wire is a loop? I seem to remember seeing a video where the player not only moved it side to side but pulled the ring in towards himself a bit.

The Ondes is a loop - I know, I've seen one.

This bit is only a guess, because all I saw of the works was the amplifier, but my assumption is that the loop moved a variable capacitor, like the tuning capacitor on an old valve radio. This altered the frequency of one high frequency oscillator. This was mixed with the output of a fixed, high frequency, oscillator and the resultant beat frequency was the audio heard. This is the same principle as used in the theremin, though in that case, it is hand capacitance that changes the frequency of the variable oscillator.

At the time the units were designed, this was about the only way to get a wide range audio oscillator.

The Prof is right on the mark. Years ago, in the time of freely available CEMs, SSMs and whatnot, I had my first fling with Synth DIY. During that time, I bought a book called "The Art of Electronic Music" that I thought had long since been lost. Lo and behold I found it in my parent's attic a couple of weeks ago. It's an absolutely marvelous book, published in 1984. It was compiled by Tom Darter, edited by Greg Armbruster with a foreward by Robert Moog. It's a perfect time capsule of a book - it came out at the zenith of analog synthesis, some little time before the appearance of the DX7. It has interviews with all the big players of the time - Moog, Buchla, Oberheim, Dave Smith, John Chowning, as well as interviews with Tomita, Carlos, Powell, Tangerine Dream, Kraftwerk, Eno, Ciani, Vangelis and a bunch of others. But the best part is an amazingly comprehensive history of electronic instruments. It's got gadgets referred in there I've never seen anywhere else. One of those gadgets is the Ondes Martenot.

This is what it has to say about the Ondes Martenot:

"The instrument uses the same heterodyning tone generation method as the Theremin: Two ultrasonic oscillators produce an audible difference tone. Maurice Martenot must have realized the difficulty that the "space controlled" Theremin presented to the performer. From his earliest models, Martenot included ways to give the performer tactile and visual feedback for accurate pitch control. On the first instruments, pitch was controlled continuously using an endless wire or band arranged on pulleys to rotate a variable capacitor within the instrument. A small plastic ring was attached to this band. The performer placed the forefinger of the right hand in the ring to move the band, rotate the capacitor, and ultimately change the pitch. To help in the location of discrete pitches, a painted "dummy" keyboard was placed under the pitch band. By moving the finger to the visual reference points provided by this dummy keyboard, the performer could easily arrive at traditional discrete pitches."

There are over two pages on the Martenot in this book (some nice pics, too). It goes on to say:

"The instrument was keyed by the left hand, which controlled a small button that provided articulation. Several "stops" governed the envelope, or loudness shape (an interesting situation: articulation and pitch control divided between the hands - more like a wind instrument). The left hand also controlled other stops which gave a choice of eight tone qualities. Timbre was controlled by switching on filter circuits that acted on harmonics produced in the first stage of the amplifer."

The article also mentions a system of indentations on the front of the cabinet below the keyboard included in later models which allowed the performer to feel interval size by counting the indentations.

Thanks for the book reference Scott - I found a second hand copy on Amazon for about $9.50 deliverd to the UK. A lot of really tasty books on Electronics and Music never made it to the UK.

Perhaps by making a second 'intonation' panel, to go with The Appendage, an affordable 'sort of' Ondes might be possible. Even on this group I don't think many people would be mad enough to try making those 'modded' loudspeakers 'The Diffusers', They might be possibly simulated using some resonant filters for 'The Palme' and some ring modulation for the 'metallique'.

Same construction probably as in any old radio ... the string can't slip because it's actually fixed (with a stiff spring to avoid the wire breaking from tension variations) to a wheel that's on the variable capacitor .. the wheel actually is a spool holding enough wire for one complete horizontal excursion (of the ring in case of the ondes martenot, of the station indicator in the case of a radio)._________________Jan

The loop on the Ondes, I think will be like the tuning mechanism on an old valve radio. It will have multiple turns around the spindle, probably there was a drum on the spindle, to provide distance gearing, with one end of the cord loop fastened there. The may be some sort of spring to maintain loop tension. As long as there is no stretch or slippage in the section of the loop back to the variable capacitor, there would be no drift.

There has to be a form of 'gearing' because the variable capacitor would probably have had a 180 degree action, and this would have to correspond to at least 24 inches of travel for the ring/loop. 6 turns on, (and off) a 2 inch drum, with a 3 to one gear would do it. It was routine technology in those days. These days your toothed belt/pulleys would make a far better reduction gear, because of the lack of backlash._________________Mike

Same construction probably as in any old radio ... the string can't slip because it's actually fixed (with a stiff spring to avoid the wire breaking from tension variations) to a wheel that's on the variable capacitor .. the wheel actually is a spool holding enough wire for one complete horizontal excursion (of the ring in case of the ondes martenot, of the station indicator in the case of a radio).

You lost me there. Wouldn't the spool have to have to have multiple turns on it to operate the 10-turn pot? I don't see anything like that in the picture. (On a radio the cap rotates 180 deg, here the rotation is 3600 deg.)

Wouldn't the spool have to have to have multiple turns on it to operate the 10-turn pot? I don't see anything like that in the picture. (On a radio the cap rotates 180 deg, here the rotation is 3600 deg.)

Don't know what picture you are referring to ... but yes it would need 10 loops in total for a 10 turn pot. Multiple turn caps were not that odd in the radios I saw as a kid. Although the cap itself would do just half a turn a gearing mechanism would make it multi turn. The constructions used to make such a gearing mechanism go smooth were works of art at times BTW._________________Jan

Ah! Spreading confusion again - I was talking about caps, not realising you were talking about pots. My Bad.

Yes - you need a drum sized so that 10 turns equates to the length of the keyboard.

The best radio dials tended to run on and off the drum, with a spring in the 'trailing' end of the loop to maintain tension.

This web page has a lot of examples of the capacitor type systems, though in this case they are driven by a knob, just imagine replacing that bit with an idler pulley and moving the dial pointer to tune. That's the way the Ondes worked.

It's cool that so many people are interested in my homemade Martenot controller. Why did I make it? Basically, I didn't want to spend $2500 on a French Connection, and to buy a real Ondes Martenot (at around $30,000, if you can even FIND one) was out of the question. I gave up on the Theremin, Circon, and Ribbon Controller for playing actual melodies on. I was not really interested in just making scary or experimental noises --- I actually wanted to play real MUSIC. But the theremin is especially hard to sound good on. It's gotta be the most difficult instrument in the world to play well. Even skilled musicians can sound cringingly bad on it.

I really wanted the expressiveness of the vibrato of the theremin, with accurate pitch control, and also with voltage control ability to interface with my big modular's sounds. So, that's why I built this instrument. What attracted me most to the Martenot, was its' most ingenious design feature: Its' fingerboard, with its carved depressions for the finger to accurately land on the concert pitch. This greatly improves pitch control. With this instrument, you can still play a bad note, but it's not as easy!

I basically sat in a room with a computer, and did as much online research that I could. This included listening to lots of Martenot music, searching YouTube, and all other web resources. I still have not actually seen a Martenot in person. I just had to guess what was inside, and how it actually worked. Then, I modified what I knew about it, for my own needs. I drew drawing after drawing of various approaches to the design, before I started building this thing.

I'm lucky that my dad is a master craftsman, particularly good at woodworking, but also he's good at constructing most anything. I've taken advantage of his (free) services many times, for things I needed built in my studio. We worked together and brainstormed quite a bit. I did most of the idea work, but he did most of the actual construction, as well as revising a few of my ideas.

Eventually, I'll be making up a web page, documenting how we built this controller. Until then, attached are a few photos of some of the instruments' features... I'm waiting for one more part to come in, and then I'll be posting another YouTube video, showing the volume control working in great detail.

If anyone has any questions, I'd be happy to answer them here. BTW, I am NOT building one for you! You have to build your own...!
I'm happy to share any information I can...

The volume lever assembly. It's a simple fulcrum design that pulls a lever potentiometer open and closed to allow the volume to be controlled. This acts as a simple envelope generator, as well as volume control.

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